This application claims the priority of German patent document 103 38 065.5, filed Aug. 19, 2004, the disclosure of which is expressly incorporated by reference herein.
The invention concerns a safety device for a tank system having a tank pipe.
German patent document DE 36 35 468 C2 discloses a tank pipe having one end that faces a filler neck and another end that faces a fuel container. The tank pipe has a pliable region which includes an internal rubber hose and a bellows-like outer hose, to compensate for deformation in the event of an accident. The bellows-like outer hose allows for a sufficient deformation path for this purpose, while the internal rubber hose serves for a good flow behavior when filling the tank. If the elasticity of the inner rubber hose is exceeded in the event of an accident, the rubber hose tears on a target breakage site. The tightness of the tank pipe remains guaranteed since the elasticity of the outer hose is designed for large deformation pathways.
A tank pipe disclosed in German patent document DE 36 35 469 A1 has a filler neck or a fuel container arranged on ends thereof. The tank pipe likewise has a pliable region including two corrugated pipes with different strength inserted one into the other, to compensate for deformations. The internal corrugated pipe has a lesser strength than the outer corrugated pipe. While the outer corrugated pipe enables a sufficient deformation path for the action of force in the event of an accident, the inner corrugated pipe detaches from the outer corrugated pipe in response to a specified force.
To summarize, the tank pipes known from the state of the art include a pliable region having two pipes lying one inside the other to compensate for deformations arising in the event of an accident.
One object of the present invention is to provide a tank pipe which offers enhanced safety for those involved in traffic in the event of a collision.
This and other objects and advantages are achieved by the safety device according to the invention, which consists of a hollow reinforcing element that is attached externally on the tank pipe. The reinforcing element conforms to the tank pipe so that it is in contact therewith over its entire circumference. (However, within the scope of the invention, it is also possible for the reinforcing element to be only partially in contact with the tank pipe.) The reinforcing element has a stiffening function.
Due to a separate mode of construction of tank pipe and reinforcing element, different materials can be used for the two components. This way the positive characteristics of the individual materials can be combined with each other. Furthermore the tank pipe can be used for different types of motor vehicles, and reinforced individually with the reinforcing element on the particularly endangered places for the respective type of motor vehicle. In the event of an accident, motor vehicle parts arranged in the vicinity of the tank pipe can come into contact with and damage to the tank pipe. Due to the special stiffening on the endangered region of the tank pipe, the tank pipe is protected from this type of damage.
In one embodiment, the reinforcing element has a basically circular cross section that is constant over its entire length. In this way, the reinforcing element and the tank pipe (which in this embodiment likewise has a constant circular cross section) are harmonized with each other, with the inside diameter of the reinforcing element corresponding to the outside of the tank pipe. The reinforcing element encloses the tank pipe like a second skin and in this way requires little space. Furthermore, the reinforcing element has a particularly stable construction due to the constant cross section in the longitudinal direction.
It is, however, also possible within the scope of the invention that the cross section of the reinforcing element is not constant over the its length, but is tapered, for example. In this way, the reinforcing element can be individually adapted to different tank pipes and the tank pipe can be freely configured. Likewise curvatures of the tank pipe can be taken into consideration in manufacturing the reinforcing element.
In order to install the reinforcing element simply and rapidly on the tank pipe, it consists of several separate components according to a further embodiment. Two sleeves can be provided as components, which are applied from the exterior to opposite sides of the tank pipe and thereby enclose it. The sleeves have a basically semicircular cross section. The longitudinal axis of the reinforcing element corresponds to the longitudinal axis of the tank pipe (which can be manufactured independently of the reinforcing element). Time is saved and costs can be reduced due to rapid installation. Providing three or four sleeves as reinforcing elements that are joined with one another during assembly is also possible. In this way, the reinforcing element can be adapted to the shape of the tank pipe.
The sleeves have recesses for accommodating fastening fixtures in accordance with a further embodiment. The installation is simplified in this way because the fastening points are already specified and fastening fixtures can simply be inserted into the receptacles.
In a further embodiment, the fastening fixtures are constructed in one piece with the tank pipe, for example, as elevations on the tank pipe. In this way, the reinforcing element can simply be clipped onto the tank pipe in one assembly step, and can also be released again. The elevations are constructed such that they snap into the recesses of the reinforcing element. The snap-fit can take place through a projection that is mounted on the elevation. This has the advantage that no additional fastening fixtures are needed for assembly, so that costs are saved. But other fastening possibilities of the sleeves are also possible, such as, for example, a gluing connection or a screwing connection.
The recesses are constructed trapezoid-like in a further embodiment.
In another embodiment, the boundary regions of the sleeves facing one another delimit a meandering separation line. For this purpose, the boundary regions of the sleeves have trapezoidal regions, and are harmonized with one another such that they engage into one another, but do not come into contact, following the installation of the tank pipe. In this way, they prevent sliding of the two sleeves toward one another in a longitudinal direction.
The fastening fixtures are constructed in one piece with one of the sleeves in a further embodiment, so that no additional fastening fixtures are needed, and costs as well as time are saved in installation. For example, the boundary regions of one of the sleeves can be bent outwardly as a fastening fixture. The sleeve has individual projecting boundary regions for this purpose that are bent toward the outside on their ends. These ends can be used as hooks or hinges for joining the two sleeves. This is a type of fastening fixture, which is simple to manufacture.
In accordance with a further embodiment, one of the sleeves has peripherally extending projections that have recesses for accommodating fastening fixtures. That is, the projections are tongue-like boundary regions of the sleeves, with recesses that are parallel to the longitudinal axis of the sleeve. The recesses can, for example, be constructed as oblong holes so that the bent boundary regions of the other sleeve can hook into the recesses, providing a simple detachable connection. The recesses may, of course, have other shapes, such as, for example, circular or rectangular. The fastening fixtures that are to be accommodated into the recesses are correspondingly adapted.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.